Abstract:

1. Painting and Polyethylene Covers Enhance Spring Green-up and Winter Survival of Warm-season Putting Green Species Figure 1. Turf surface temperature as affected by polyethylene covers, turf variety, and date in Knoxville, TN, in 2008. NS indicates no significant difference. *, *** indicate significance at the 0.01 and 0.0001 P level, respectively. Figure 2. Soil temperature as affected by polyethylene covers, turf variety, and date in Knoxville, TN, in 2008. NS indicates no significant difference. †, *** indicate significance at the 0.05 and 0.0001 P level, respectively. September Figure 3. Timeline of full turf green-up in Knoxville, TN, in 2009. Error bars represent an LSD of 3 weeks. John M. Kauffman*, John C. Sorochan, and James T. Brosnan Dept. of Plant Sciences, University of Tennessee Abstract: Low temperature injury, winterkill, and slow spring green-up are common problems facing managers of warm-season putting greens in the transition zone. Putting greens are often covered with polyethylene blankets during cold periods to protect against low temperature injury. Painting greens with a green latex paint adds color during the dormancy period and may hasten turf green-up in the spring. The objective of this study was to determine the impact of polyethylene covers and painting on low temperature injury and pace of spring green-up of four warm-season putting green turfs in the transition zone. ‘Champion’ and ‘TifEagle’ bermudagrass (Cynodon dactylon C. traansvalensis Burtt-Davy), ‘SeaDwarf’ seashore paspalum (Paspalum vaginatum Sw.) , and ‘Diamond’ zoysiagrass (Zoysia matrella (L.) Merr.) were established in July 2008 on a modified California rootzone at the East Tennessee Research and Education Center in Knoxville, TN. Treatments consisted of covers alone, painting alone, the combination of painting and covering, and an untreated control. Plots were covered when temperatures were forecasted to be -3 C or below and were painted on 28 January, 2009. Covering plots caused turf to emerge from dormancy sooner than painting plots for all varieties except ‘Diamond’ zoysiagrass, in which no difference in green-up time existed. Covered plots also maintained higher soil and surface temperatures than uncovered plots. Painted and uncovered plots had higher surface temperatures than untreated plots only on sunny days. Covered bermudagrass plots emerged from dormancy a full three weeks sooner than uncovered plots. ‘SeaDwarf’ seashore paspalum emerged from dormancy quicker when painted than covered, yet took eight weeks longer to emerge from dormancy when uncovered than covered. ‘Diamond’ zoysiagrass was the first to emerge from dormancy and was not affected by painting or covering. Using polyethylene turf blankets can improve winter survival and hasten spring green-up for ultradwarf bermudagrass and seashore paspalum in the transition zone. Introduction: Because cold hardiness and winterkill are concerns for managers of warm-season putting greens in the transition zone, practices to enhance winter survival are important. Improving spring greenup may allow play to resume earlier and allow the plant to begin producing photosynthates earlier in the year. Covering the turf is a common method to increase winter survival. Winter protective blankets trap heat energy and keep the soil and air around the plant warmer than the ambient air temperatures (Goatley et al., 2007). Pine straw was used as early as 1929 for protection of bermudagrass putting greens in the winter (Beckett, 1929). Enhanced fall color retention, winter survival, and spring regrowth of covered bermudagrass maintained at heights >19 mm have been reported (Goatley et al., 2005). Additionally, painting warm-season putting greens has become increasingly popular in the transition zone as a method of delivering a green putting surface to the golfer without introducing additional cost and competition to the warm-season turf by overseeding. Results and Discussion: Polyethylene covers, turf variety/species, and observation date, along with their interaction, significantly impacted turf surface temperature in 2008 (P<0.01), although the presence or absence of latex paint did not significantly alter surface temperature (P>0.1). Covered plots had a higher surface temperature than uncovered plots on many rating dates (Fig. 1). On dates in which some covered plots had higher surface temperatures than other covered plots as well as the uncovered plots, ‘Diamond’ and ‘SeaDwarf’ returned the most consistent high temperature values likely because they maintained their green color longer than the bermudagrasses. Covers, turf variety/species, and rating date also significantly impacted soil temperature in 2008 (P<0.001). Covered plots returned significantly higher soil temperatures than uncovered plots on all but three rating dates (Fig. 2). Among the uncovered plots, ‘SeaDwarf’ often returned the highest soil temperatures, likely because of its color retention in the fall. Additionally, covers and turf variety/species significantly impacted the time of full spring green-up (P<0.005). Covered ‘Diamond’ achieved full recovery from dormancy in early April, four weeks before any other variety (Fig. 3). Both ‘Champion’ and ‘TifEagle’ achieved full green-up in May when covered, but took an additional three weeks when uncovered. Covered ‘SeaDwarf’ recovered in May, as did the bermudagrass varieties, but the uncovered ‘SeaDwarf’ did not recover fully until August. Results: Objectives: Determine impact of polyethylene covers used during periods of low temperature and the use of latex paint on low temperature injury and pace of spring green-up of warm-season putting green species in the transition zone. • Materials and Methods: • This study was conducted on a newly constructed California putting green at the East Tennessee Research and Education Center in Knoxville. ‘Champion’ and ‘TifEagle’ bermudagrass (Cynodon dactylon C. traansvalensis Burtt-Davy), ‘SeaDwarf’ seashore paspalum (Paspalum vaginatum Sw.) , and ‘Diamond’ zoysiagrass (Zoysia matrella (L.) Merr.) were established in 3 x 1.5 m plots from sod in July 2008 in a randomized complete block design with six replications. N, P, and K were applied at 288.8 kg ha-1, 72.2 kg ha-1, and 144.4 kg ha-1 yearly to the bermudagrasses and seashore paspalum. The ‘Diamond’ zoysiagrass received 144.4 kg ha-1 N, 72.2 kg ha-1, P, and 144.4 kg ha-1 K yearly. Plots were maintained as a putting green and were mowed six times per week at 3.1 mm with a Jacobsen Greens King IV triplex mower. • Treatments were arranged in a randomized complete block split plot design, in which polyethylene covers were applied in a factorial arrangement to the whole plot factor variety/species and the presence or absence of latex paint applications comprised the split plot. Plots were covered when low temperatures were forecasted to be -3 C or less and remained covered if high temperatures were forecast to be 3 C or lower. Paint applications were made on 28 January, 2009. • Turf surface temperature underneath cover was measured weekly • Soil temperatures at a 2.5 cm depth were measured weekly • Visual observation of green cover was taken weekly to assess emergence from dormancy. • Data were analyzed using the mixed model procedure in SAS Statistical Software to determine the effect of the paint, cover, and variety on the respective evaluations. For each evaluation, differences were deemed significant when the P-value corresponding to the ANOVA F-test was less than 0.05. When cultivation treatment main effects were significant, means were separated using Fisher’s protected LSD test (α = 0.05). Figure 5. Uncovered SeaDwarf (above) versus covered SeaDwarf (below). Photo taken on 6/1/2009. • Conclusions: • Polyethylene covers increase surface temperature when used in winter • Covering plots increases soil temperature • Polyethylene covers enhance spring green-up for all varieties/species except ‘Diamond’ • Latex paint applications did little to influence surface temperature, soil temperature, or spring green-up Literature Cited: Beckett, H. 1929. Covering bermudagrass greens for winter protection. Bull. USGA Green Sect. 9:175. Goatley, J.M., J.P. Sneed, V.L. Maddox, B.R. Stewart, D.W. Wells, H.W. Philley. 2007. Turf covers for winter protection of bermudagrass golf greens. Applied Turf. Sci. 1-9. Goatley, J.M., V.L. Maddox, D.L. Lang, R.E. Elmore, and B.R. Stewart. 2005. Temporary covers maintain fall bermudagrass quality, enhance spring greenup, and increase stem carbohydrate levels. Hort Science. 40:227-231 Figure 4. Covered unpainted TifEagle plot (above) has less green turf cover than uncovered unpainted Diamond. Photo taken on 2/15/2009.